The Clinical and Repository Core seeks to facilitate the laboratory investigations of all three Consortium projects, while also benefitting from the management of the Administrative Core and providing opportunities for scientific leadership development in collaboration with the Mentorship Core through the following Specific Aims: 1) To recruit, screen, and enroll into research protocols subjects from Ugandan HIV-positive populations with or at risk for AIDS-Defining malignancies; 2) To follow participants prospectively on studies, maintaining close adherence to study procedures; 3) To help maintain a robust biospecimen repository to facilitate the study of the natural history of AIDS-defining malignancies in Uganda and to make these specimens available to the laboratories involved in all three program projects; 4) To facilitate the collection and analysis of data obtained from participants in clinical research studies to allow for the characterization of the clinical, epidemiologic and medical determinants of response to treatment of AIDS-defining malignancies in Uganda. To achieve these aims, the Core will leverage a well-established translational and clinical research infrastructure that has been built by the collaboration between the Hutchinson Center and the Uganda Cancer Institute. A staff of more than 50 individuals who have all been trained in HIV-associated malignancy research and good clinical and laboratory practice work at the collaboration's research clinic in Kampala, which has studied more than 7,000 participants and currently maintains a biorepository with more than 150,000 specimens from patients with HIV and cancer. The Core will support selected staff to provide specimens and data from patients in ongoing prospective cohort studies with or at risk for Kaposi Sarcoma, non-Hodgkin Lymphoma and invasive cervical cancer. At the same time, trainees in clinical research and laboratory science will be integrated into the Core's activities in collaboration with the Mentorship Core to continue to develop a cadre of outstanding Ugandan investigators to lead future studies in HIV-associated malignancies.